Surge damper for hydraulic systems



Mmca 2%, B95 J. JQHSGN SMPW sURGE DAMPER FOR HYDRAULIC svsmas Filed May14, 1946 latented Mar. 28, 1956 2,501,773 sUnoE mman Fon mimmo sYs'rnMs.i ack Johnson, Long Beach, Calif., assigner to Lou Son Development Co.,Long Beach, Calif., a corporation of California Application Mey 14,194s,.seria1 No. 669,494

4 claims. (c1. 13s-ao) This invention relates to a surge damper forhydraulic systems whereby the surge or impulses or hydraulic shocks of ahydraulic system are absorbed or damped, and particularly' the surge orimpulses caused by the pump.

An object of my invention is to provide a surge damper wherein thehydraulic fluid under pressure is caused to circulate aroundv ayieldable diaphragm or bag, thus exerting pressure over substantiallythe entire circumference of the diaphragm. v

Another object of my invention is to provide a novel surge damper of thecharacter stated in which the yieldable diaphragm is substantiallycylindrical in form and the diaphragm being inflated or expanded by airor gas pressure.

Another object of my invention is to provide a surge damper in which theentire diaphragm unit may be quickly and easily removed and replaced,when necessary.

A feature of my invention resides in the novel consh'uction of my surgedamper wherein a plurality of surge damping umts may be arranged insequence ii high pressures are encountered, in the hydraulic system.

@ther objects, advantages and features of invention may appear from theaccompanying wing, the subjoined detailed description, and the appendedclaims.

The drawing is a longitudinal, sectional view of my surge damper.

ierring more particularly to the drawing, the numeral i indicates ahousing, one end of which is open and the open end closed by a cap 2,which is threaded onto the housing i as shown at t. The complete housingassembly is thus somewhat cylindrical in form or may be described aselliptical in longitudinal section. A handle d on the cap 2 enables thecap to be threaded onto the housing and also permits this cap to lbeeasily handled.

My surge damper is arranged in a hydraulic system so that the uid inthis system can enter theliousing l and this is accomplished by a pipeil, which screws into the housing I, this pipe extending into thepressure line of the hydraulic system. Particularly my surge damper isused in the drilling of oil wells where drilling mud is pumped underhigh pressure into the well while the drilling operations continue. Thedrilling mud is pumped into the `Well under high pressure from asuitable pump, and the pipe 5 extends into the pressure line which leadsinto the well.

.dt the top of the housing i, I provide a plug 6, which contains apressure gauge 1. 1f the fluid pressures of the hydraulic. system arehigh and one unit oi' the surge damper will not suffice, then one ormore units may be superimposed on the ilrst unit by removing the plug 6,and by providing a short pipe which extends fromone damper unit toanother. In this manner, the pressures are distributed between aplurality of units.

The diaphragm may be disposed in a removable unit B preferably incartridge form including a solid mandrel 9. A threaded pin I0 extendsfrom one end of the `mandrel 9, -anda second threaded pin Il extendsfrom thev other end of the mandrel. A diaphragm I2 of cylindrical or bagshape may be formed of rubber or yieldable plastic and is mounted on'themandrel 9, and when the diaphragm notfinilated, it closely surrounds themandrel'. In the drawing,

the bag is shown in its inflated position. Alvalye g I3 is mounted inthe pin I Land this valve checks the air going into the portl IB, whichlport 'opens into the diaphragm i2. 'Airor gasunder' pressure is forcedthrough the valve I3, and the port l "f it, and inilates -the'diaphragmi2, asshowm- A cage 22 including end bells it and I 9 and a cylinder 26surrounds themandrel 9 and is mounted.v

thereon, and the diaphragm, `when inated, presses against the inside ofthe cage, substantially'as shown in the drawing. The cylinder 2l v isperforated, as'shown at'i5, so that the fluid, underpressure,'canpress'againstlthe bag, causing the same to collapse orpartially collapse against the pressure within the bag. Thelperforati'ons4 I5 are arranged circumferentially in the cage 22, andthus permit the hydraulic uid to press vagainst substantially the entireexternal surface of the bag i2.

The cage 22 is assembled'on the mandrel 9 by means of the nuts I8 andIl, which screw onto the pins it, il respectively, and hold the endbells I8 and is of the cage 22 on the perforated cylindrical sleeve 2u.It is thus possible to assemble the cage on the mandrel, and the endbells I8, I9 also press against the ends of the cylindrical diaphragmit, thus holding the ends of the diaphragm against thepends of themandrel, and preventing leakage of air or gas when the dia-4 phragm isinated.

The mandrel 9 is held in the housing I in the following manner:

A set screw il is threaded through the end of the housing I and bearsagainst the end of the from contamination by the liquid being damped.The diaphragm I2 is inflated to the proper pressure before the entirecartridge assembly is assembled in the housing I. Thereafter, it isseldom necessary to repressurize the diaphragm or bag I2. If thediaphragm unit is injured in any manner, the cap 2 is removed and theentire diaphragm unit can then be removed from the housing for purposesof repair or replacement.

While my invention has been described with reference to a presentlypreferred embodiment. I do not limit myself t this embodiment, since Iinclude within the true spirit and scope of my invention all similar andequivalent structures.

Having described my invention, I claim:

1. A diaphragm cartridge adapted to be inserted in a surge damperhousing comprising: a multi-piece cage; a mandrel extendinglongitudinally of the cage; a resilient cylinder disposed in the cagebetween the mandrel and the cage; and means securing the mandrel andcage together, whereby the ends of the cylinder may be pinched betweenthe cage and the mandrel to retain the cylinder within the cage.

2. A diaphragm cartridge adapted to be inserted in a housing comprising:a mandrel threaded at either end; apertured end bells adapted to bepassed over the threaded ends of the mandrel to define a cage; aninflatable bag disposed within the cage exterior of the mandrel; andmeans for inserting a gas under pressure into the interior of theinflatable bag.

3. A surge damper comprising: a housing having a fluid inlet and havinga main portion and a removable cap with thread means on the innersurface thereof; a diaphragm cartridge insertable within the housing andincluding an inflated bag and thread means on one end; and centeringmeans carried by the main housing portion, whereby the cartridge may berigidly secured within the housing by engagement of the thread meanswith the threaded portion of the cap, and

'also by contact of the centering means with the cartridte.

4. A surge damper for hydraulic systems comprising: a stationary housingmember having a fluid inlet; a housing cap adapted to be removablysecured to the stationary housing member and having a tapped boss on theinner surface thereof; a mandrel threaded on both ends and adapted to bethreaded into the tapped boss of the housing cap; a cage mounted on themandrel and including end bells and a cylindrical perforated centralportion; a resilient bag pinched between the ends of the mandrel and theend bells; a passage'extending through one threaded end of the mandrelto the interior of the bag; a valve disposed in the passage so that airinserted within the bag may be retained therein; a gasket disposedbetween the mandrel end threaded to the housing cap and the housing capto prevent leakage of hydraulic fluid to the valve; and a centeringscrew extending through the main housing portion to contact the otherend of the mandrel to thereby center the mandrel and the portions.attached thereto which define a removable cartridge.

JACK JOHNSON.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS

